MECO - A worldwide leader in water purification

 

Enhanced Membrane

Military Tested Means More Reliability and Reduced Maintenance Costs.

MECO's Enhanced Membrane Systems are based on the latest systems employed by the U.S. Military and can treat any water anywhere. Presently operating in West Africa river estuaries and other harsh locations around the world, these watermakers utilize an ultrafiltration membrane that pre-treats harsh feedwaters, river estuaries or those close-to-shore. And unlike traditional systems that often foul or require intense operator oversight and frequent cleaning, MECO's Enhanced Membrane Systems run with reduced maintenance.


Specifically designed to treat high turbidity feedwater, MECO's Enhanced Membrane Systems allow for continuous operation and cleaning without operator involvement. The fully automated design of MECO's system effectively removes particulates up to 150 NTU, extending the system's life and significantly decreasing maintenance. Moreover, the units are no larger than conventional water treatment systems.

Ultrafiltration Membranes

Hollow fiber ultrafiltration membranes pre-treat feedwater removing up to 150 NTU of turbidity.

Automatic Operation

The PLC controlled process automatically backwashes the UF modules every few minutes, removing any surface contamination on the membranes.

Small Footprint - Reduced Weight

Compact UF membranes effectively replace conventional filters, resulting in a significant reduction in weight and similar footprint.

The LWP technology enables the system to treat any water - anytime. The system utilizes membrane-based filtration which removes suspended solids from water as it passes through a porous membrane (which is classified by its pore size). Microfiltration and ultrafiltration membranes are effective for the removal of suspended solids and some high molecular weight dissolved solids.

Microfiltration

Microfiltration employs the use of a porous fiber that filters out most unwanted constituents in feed water. There are several types of microfiltration membranes, such as hollow fiber membranes and spiral wound membranes. These membranes have pore sizes in the range of 0.1 to 1.0 microns.

As an example, a spiral-wound membrane consists of flat sheets wrapped in a spiral configuration similar to a reverse osmosis membrane. The pores in a hollow fiber membrane or spiral wound membrane should be consistently on the order of 0.1 to 0.2 µm in size.

The purpose of microfiltration
Microfiltration provides the end user with the ability to consistently and efficiently remove suspended solids, bacteria, yeast, many viruses, and harmful biological contaminants such as Giardia Lamblia and Cryptosporidium from feed water. Typical fiber material is dependant on the manufacturer and application, but can be commonly found in PVDF (Polyvinylidenefluoride), Polyacrylonitrile or Polyethylene. Material choice can be dictated by the Molecular Weight Cutoff of the membrane material. A membrane containing a smaller MWCO provides better overall filtration.

Microfiltration applications
There are a multitude of applications for microfiltration, ranging from pretreatment for the offshore industry to the pharmaceutical industry. This filtration method is commonly used at municipal drinking and wastewater treatment plants as both a pretreatment and polishing mechanism.

A cost effective solution
Microfiltration can be very cost effective in comparison to multi-media and cartridge filtration systems. That's because microfiltration provides the ability to regularly clean the membrane and continue service for much longer periods of time. Filter cartridges typically must be replaced often depending on the level of suspended solids, and do not provide the level of filtration equal to microfiltration. This lack of filtration can lead to more frequent downstream equipment maintenance due to faster foulant build-up.

A closer look at a microfiltration system
A typical microfiltration system consists of a skid frame containing racks that can hold several membranes with valves and instruments to help monitor system properties such as pressure, flow, and backwash frequency. Typical feed pressures for ultrafiltration systems are from 30 to 50 psi. Filtration can occur in one of two ways with a hollow fiber membrane: outside to in, or inside to out. Ultrafiltration systems are usually operated in a cross flow mode so that a small amount of concentrated dirty water is continually sent to waste.

The total amount of filtrate (filtered water) that the membrane makes each day per square foot of membrane surface area is know as flux. Flux is measured in gallons of filtrate per square foot of membrane surface per day. Membrane manufacturers have a ceiling value for the acceptable flux range of any certain element.

Flushing and backwashing
While a microfiltration system is in operation, it is often flushed and backwashed to remove deposits from the fiber surfaces. However, the system will eventually need to be cleaned to caked solids that flushing and backwashing can no longer remove. This returns the system to its most effective level performance.

The main parameter used to show the effectivity and operational cleanliness of a system is transmembrane pressure, or TMP. When this pressure rises to 30 psi or higher, the suspended solids and other impurities in the water have "caked" on the membrane surface. The loss in pressure as the water moves across the membrane surface exemplifies the level of this caked material. The pores in the membrane wall are effectively clogged and filtrate flow is drastically reduced when the TMP has risen to the upper end of the allowable range.

At this point, the unit can be backwashed with permeate for a specified amount of time and at a particular flow rate. This basically works in reverse of the normal flow path and forces filtrate at a higher flow rate back through the pores, dislodging the cake on the membrane surface. The resulting freed particulate is sent to drain.

To further aid in cleaning the membrane surface, a pressurized air scour can also be utilized to help dislodge additional caked-on material. Low-pressure air is injected into the feed flow at the normal flow rate. The air helps to agitate the membrane fibers, further loosening any remaining cake. Filtrate is not made during this scouring. The air scour can be performed on a less frequent basis depending on how severe the turbidity of the water is.

Using chemicals to clean a system
Although backwashing and air scouring cleans the membranes effectively, there comes a point when it will take a chemical cleaning to restore the membranes to their normal filtration capabilities. Here, a closed loop is formed and cleaning chemicals are circulated through the system. The filtrate is dumped to drain and the reject is recirculated back into the cleaning tank.

The cleaning is stopped, the unit is restored to normal operating mode, and all filtrate is dumped to drain for a set amount of time. Normal operation can then be resumed and the new TMP should read near the level of a new membrane. When backwashing, air scouring and chemical cleaning will no longer reduce the TMP, the membrane is considered to be fouled and must be replaced.

Cleaning frequency
There are several factors that affect the cleaning frequency for a membrane-based system. The main ones are operational recovery and the filtrate flux rate. These system factors are optimized to produce the maximum amount of filtrate with the smallest possible cleaning frequency per the end user's needs.

As a rule of thumb, the higher the system recovery and flux rate, the shorter the productive run time will be. Subsequent cleaning frequency will also increase. By increasing the reject rate, you can allow more of the concentrated, rejected material to be removed via the higher flow rate.

In doing so, it will take a longer time to grow a large film of reject material on the membrane surface thus improving the membrane's productive life between cleanings. Operational recovery is the ratio of filtrate made to the feed flow rate expressed as a percentage. Therefore, if the recovery is raised, permeate output increases accordingly, as does the flux rate.

Ultrafiltration

Ultrafiltration employs the use of a porous fiber that filters out most unwanted constituents in feed water. These membranes have pore sizes in the range of 0.01 to 0.1 microns. There are several types of ultrafiltration membranes such as hollow fiber membranes and spiral wound membranes.

As an example, a spiral-wound membrane consists of flat sheets wrapped in a spiral configuration similar to a reverse osmosis membrane. The pores in a hollow fiber membrane or spiral wound membrane should be consistently on the order of 0.02 to 0.04 µm in size.

The purpose of ultrafiltration
Ultrafiltration provides the end user with the ability to consistently and efficiently remove suspended solids, bacteria, yeast, many viruses, and harmful biological contaminants such as Giardia Lamblia and Cryptosporidium from feed water. Typical fiber material is dependant on the manufacturer and application, but can be commonly found in PVDF (Polyvinylidenefluoride), Polyacrylonitrile or Polyethylene. Material choice can be dictated by the Molecular Weight Cutoff of the membrane material. A membrane containing a smaller MWCO provides better overall filtration.

Ultrafiltration applications
There are a multitude of applications for ultrafiltration ranging from pretreatment for the offshore industry to the pharmaceutical industry. This filtration method is commonly used at municipal drinking and wastewater treatment plants as both a pretreatment and polishing mechanism.

A cost effective solution
Ultrafiltration can be very cost effective in comparison to multi-media and cartridge filtration systems due to having the ability to regularly clean the membrane and continue service for much longer periods of time. Filter cartridges typically must be replaced quite often depending on the level of suspended solids and do not provide the level of filtration equal to ultrafiltration. This lack of filtration can lead to more frequent downstream equipment maintenance due to faster foulant build-up.

A closer look at a ultrafiltration system
A typical ultrafiltration system consists of a skid frame containing racks that can hold several membranes with valves and instruments to help monitor system properties such as pressure, flow, and backwash frequency. Typical feed pressures for ultrafiltration systems are from 30 to 50 psi. Filtration can occur in one of two ways with a hollow fiber membrane: outside to in, or inside to out. Ultrafiltration systems are usually operated in a cross flow mode so a small amount of concentrated dirty water is continually sent to waste.

The total amount of filtrate (filtered water) that the membrane makes each day per square foot of membrane surface area is know as flux. Flux is measured in gallons of filtrate per square foot of membrane surface per day. Membrane manufacturers have a ceiling value for the acceptable flux range of any certain element.

Flushing and backwashing
While a ultrafiltration system is in operation, it is often flushed and backwashed to remove deposits from the fiber surfaces. However, the system will eventually need to be cleaned to caked solids that flushing and backwashing can no longer remove. This returns the system to its most effective level of performance.

The main parameter used to show the effectivity and operational cleanliness of a system is transmembrane pressure, or TMP.When this pressure rises to 30 psi or higher, the suspended solids and other impurities in the water have "caked" on the membrane surface. The loss in pressure as the water moves across the membrane surface exemplifies the level of this caked material. The pores in the membrane wall are effectively clogged and filtrate flow is drastically reduced when the TMP has risen to the upper end of the allowable range.

At this point the unit can be backwashed with permeate for a specified amount of time and at a particular flow rate. This basically works in reverse of the normal flow path and forces filtrate at a higher flow rate back through the pores, dislodging the cake on the membrane surface. The resulting freed particulate is sent to drain.

To further aid in cleaning the membrane surface, a pressurized air scour can also be utilized to help dislodge additional caked-on material. Low-pressure air is injected into the feed flow at the normal flow rate. This air helps to agitate the membrane fibers, further loosening any remaining cake. Filtrate is not made during this scouring. The air scour can be performed on a less frequent basis depending on how severe the turbidity of the water is.

Using chemicals to clean a system
Although backwashing and air scouring cleans the membranes effectively, there comes a point when it will take a chemical cleaning to restore the membranes to their normal filtration capabilities. Here, a closed loop is formed and cleaning chemicals are circulated through the system. The filtrate is dumped to drain and the reject is recirculated back into the cleaning tank.

The cleaning is stopped, the unit is put back into normal operating mode, and all filtrate is dumped to drain for a set amount of time. Normal operation can then be resumed and the new TMP should read near the level of a new membrane. When backwashing, air scouring and chemical cleaning will no longer reduce the TMP, the membrane is considered to be fouled and must be replaced.

Cleaning frequency
There are several factors that affect the cleaning frequency for a membrane-based system. The main ones are operational recovery and the filtrate flux rate. These system factors are optimized to produce the maximum amount of filtrate with the smallest possible cleaning frequency per the end user's needs.

As a rule of thumb, the higher the system recovery and flux rate, the shorter the productive run time will be. Subsequent cleaning frequency will also increase. By increasing the reject rate, you can allow more of the concentrated, rejected material to be removed via the higher flow rate.

In doing so, it will take a longer time to grow a large film of reject material on the membrane surface, thus improving the membrane's productive life between cleanings. Operational recovery is the ratio of filtrate made to the feed flow rate expressed as a percentage. Therefore, if the recovery is raised, permeate output increases accordingly, as does the flux rate.

Q: Is there any benefit to using Membrane Filtration instead of the standard multi-media filtration?

A: The Membrane Filter removes suspended solids down to .01 micron as well as other contaminants such as bacteria and some viruses. Multi-media filters (MMF) / cartridge filters will only remove suspended solids to approximately 1-5 micron. When feeding an RO unit, the MF system will significantly reduce the bio-fouling and reduce the SDI to below 1.

Q: Is filtration necessary ahead of the RO membrane?

A: Yes, small particulate matter will embed itself into the first element of the RO array. This will reduce the life of this element as well as increase the pressure drop through the RO unit.

Q: What is the life of Ultrafiltration membrane?

A: The Ultrafiltration membranes will last between 3 to 5 years.

Q: How long between cleaning cycles of the Reverse Osmosis Membrane?

A: The RO membranes utilized in the Enhanced Membrane System will only require cleaning once or twice per year.

Ultrafiltration Membrane

Most surface water used for the production of drinking water requires filtration to remove turbidity and suspended solids before the reverse osmosis module can utilize the water. In conventional treatment, offshore systems employ multimedia filtration to remove suspended solids. In high turbidity waters, these systems require constant monitoring, evaluation and cleaning by operators to prevent fouling of the reverse osmosis membrane. Hollow Fiber Ultrafiltration Membrane provides a positive barrier against viruses, bacteria, turbidity, and other water-borne microorganisms. Therefore, the system requires only minimal operator monitoring and can run unattended.

Automatic Flushing Cycle

All Enhanced Membrane Systems units come standard with PLC automated flushing cycle, which utilizes potable water to back flush the Ultrafiltration Modules. This effectively removes any particulates and organics, which can build up on the membrane surface. Multiple modules allow the continuous water production. The flushing cycle is transparent to the operators. Hence, the UF modules used as pretreatment can significantly extend the useful life of RO elements, minimize operational oversight and increase reliability.

High Cross Flow

Cross flows are set to meet or exceed manufacturer’s minimum requirements for scale prevention. MECO RO units come standard with permeate and reject flow meters. This ensures that membrane cross flows are set at the proper rate and that the RO remains at proper recovery.

Standard Features include

  • Hollow Fiber Ultrafiltration Membrane pretreatment system
  • Sodium bisulfite injection for de-chlorination during freshwater flush
  • No pre-treatment chemicals are required.
  • High quality materials of construction (2205 SS high pressure piping).
  • Utilizes commercially available membranes.
  • Integral cleaning system with pump, tank and instrumentation.
  • A direct coupled positive displacement pump
  • Automatic operation.
  • Packaged for easy installation.
  • Membranes are housed in side port entry pressure vessels.

Anytime. Anywhere.

  • 24 hours, 7 days a week access to effectively manage your water system.

Real Time Access to:

  • Purchase spare parts online
  • Track status of outstanding orders
  • Review shipping information
  • Review invoice/payment history
  • Review online maintenance records
  • Request technical information
  • Online electronic manuals
  • Remote system monitoring capabilities

MECO understands the importance of providing our customers with the parts and services required to maintain systems operating at optimum capacity. Our online service center - MECO MASTERsupport™ -is a good example of that. It enables you to monitor your system remotely, place orders, access service records and view your system's manuals when it's convenient for you. Anytime. Anywhere.

With a simple point and click, our entire parts inventory is available to you. Through the online service center, you also get real-time access to invoices, orders, shipping status, system manuals and service trip reports. Everything you need to know to effectively manage and maintain your treatment plant is right at your fingertips.

It's another example of MECO's commitment to providing the highest quality spare parts and cost effective support throughout the life-cycle of the product.

» Launch MASTERsupport™ Online

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